Scale inveriant object detection

ABSTRACT

Systems, and method and computer readable media that store instructions for scale invariant object detection.

CROSS REFERENCE

This application claims priority from U.S. provisional patent 62/827,122 filing date Mar. 31, 2019 filing date Mar. 31, 2019 which is incorporated herein by reference.

BACKGROUND

Object detection has extensive usage in variety of applications, starting from security, sport events, automatic vehicles, and the like.

Vast amounts of media units are processed during object detection and their processing may require vast amounts of computational resources and memory resources.

Furthermore—many object detection process are sensitive to various acquisition parameters such as angle of acquisition, scale, and the like.

There is a growing need to provide robust and efficient object detection methods.

SUMMARY

There may be provided systems, methods and computer readable medium as illustrated in the specification.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments of the disclosure will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which:

FIG. 1A illustrates an example of a method;

FIG. 1B illustrates an example of a signature;

FIG. 1C illustrates an example of a dimension expansion process;

FIG. 1D illustrates an example of a merge operation;

FIG. 1E illustrates an example of hybrid process;

FIG. 1F illustrates an example of a first iteration of the dimension expansion process;

FIG. 1G illustrates an example of a method;

FIG. 1H illustrates an example of a method;

FIG. 1I illustrates an example of a method;

FIG. 1J illustrates an example of a method;

FIG. 1K illustrates an example of a method;

FIG. 1L illustrates an example of a method;

FIG. 1M illustrates an example of a method;

FIG. 1N illustrates an example of a matching process and a generation of a higher accuracy shape information;

FIG. 1O illustrates an example of an image and image identifiers;

FIG. 1P illustrates an example of an image, approximated regions of interest, compressed shape information and image identifiers;

FIG. 1Q illustrates an example of an image, approximated regions of interest, compressed shape information and image identifiers;

FIGS. 1R and 1S illustrate examples of methods;

FIG. 2A illustrates an example of images of different scales;

FIG. 2B illustrates an example of images of different scales;

FIG. 2C illustrates an example of a method;

FIG. 2D illustrates an example of a method;

FIG. 2E illustrates an example of a method;

FIG. 2F illustrates an example of a method;

FIG. 2G illustrates an example of different images;

FIG. 2H illustrates an example of a method;

FIG. 2I illustrates an example of a method;

FIG. 2J illustrates an example of a method;

FIG. 2K illustrates an example of different images acquisition angles;

FIG. 2L illustrates an example of a method;

FIG. 2M illustrates an example of a method; and

FIG. 2N illustrates an example of a system.

DESCRIPTION OF EXAMPLE EMBODIMENTS

In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention.

The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings.

It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

Because the illustrated embodiments of the present invention may for the most part, be implemented using electronic components and circuits known to those skilled in the art, details will not be explained in any greater extent than that considered necessary as illustrated above, for the understanding and appreciation of the underlying concepts of the present invention and in order not to obfuscate or distract from the teachings of the present invention.

Any reference in the specification to a method should be applied mutatis mutandis to a device or system capable of executing the method and/or to a non-transitory computer readable medium that stores instructions for executing the method.

Any reference in the specification to a system or device should be applied mutatis mutandis to a method that may be executed by the system, and/or may be applied mutatis mutandis to non-transitory computer readable medium that stores instructions executable by the system.

Any reference in the specification to a non-transitory computer readable medium should be applied mutatis mutandis to a device or system capable of executing instructions stored in the non-transitory computer readable medium and/or may be applied mutatis mutandis to a method for executing the instructions.

Any combination of any module or unit listed in any of the figures, any part of the specification and/or any claims may be provided.

The specification and/or drawings may refer to an image. An image is an example of a media unit. Any reference to an image may be applied mutatis mutandis to a media unit. A media unit may be an example of sensed information. Any reference to a media unit may be applied mutatis mutandis to a natural signal such as but not limited to signal generated by nature, signal representing human behavior, signal representing operations related to the stock market, a medical signal, and the like. Any reference to a media unit may be applied mutatis mutandis to sensed information. The sensed information may be sensed by any type of sensors—such as a visual light camera, or a sensor that may sense infrared, radar imagery, ultrasound, electro-optics, radiography, LIDAR (light detection and ranging), etc.

The specification and/or drawings may refer to a processor. The processor may be a processing circuitry. The processing circuitry may be implemented as a central processing unit (CPU), and/or one or more other integrated circuits such as application-specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), full-custom integrated circuits, etc., or a combination of such integrated circuits.

Any combination of any steps of any method illustrated in the specification and/or drawings may be provided.

Any combination of any subject matter of any of claims may be provided.

Any combinations of systems, units, components, processors, sensors, illustrated in the specification and/or drawings may be provided.

Low Power Generation of Signatures

The analysis of content of a media unit may be executed by generating a signature of the media unit and by comparing the signature to reference signatures. The reference signatures may be arranged in one or more concept structures or may be arranged in any other manner. The signatures may be used for object detection or for any other use.

The signature may be generated by creating a multidimensional representation of the media unit. The multidimensional representation of the media unit may have a very large number of dimensions. The high number of dimensions may guarantee that the multidimensional representation of different media units that include different objects is sparse—and that object identifiers of different objects are distant from each other—thus improving the robustness of the signatures.

The generation of the signature is executed in an iterative manner that includes multiple iterations, each iteration may include an expansion operations that is followed by a merge operation. The expansion operation of an iteration is performed by spanning elements of that iteration. By determining, per iteration, which spanning elements (of that iteration) are relevant—and reducing the power consumption of irrelevant spanning elements—a significant amount of power may be saved.

In many cases, most of the spanning elements of an iteration are irrelevant—thus after determining (by the spanning elements) their relevancy—the spanning elements that are deemed to be irrelevant may be shut down a/or enter an idle mode.

FIG. 1A illustrates a method 5000 for generating a signature of a media unit.

Method 5000 may start by step 5010 of receiving or generating sensed information.

The sensed information may be a media unit of multiple objects.

Step 5010 may be followed by processing the media unit by performing multiple iterations, wherein at least some of the multiple iterations comprises applying, by spanning elements of the iteration, dimension expansion process that are followed by a merge operation.

The processing may include:

-   -   Step 5020 of performing a k'th iteration expansion process (k         may be a variable that is used to track the number of         iterations).     -   Step 5030 of performing a k'th iteration merge process.     -   Step 5040 of changing the value of k.     -   Step 5050 of checking if all required iterations were done—if so         proceeding to step 5060 of completing the generation of the         signature. Else—jumping to step 5020.

The output of step 5020 is a k'th iteration expansion results 5120.

The output of step 5030 is a k'th iteration merge results 5130.

For each iteration (except the first iteration)—the merge result of the previous iteration is an input to the current iteration expansion process.

At least some of the K iterations involve selectively reducing the power consumption of some spanning elements (during step 5020) that are deemed to be irrelevant.

FIG. 1B is an example of an image signature 6027 of a media unit that is an image 6000 and of an outcome 6013 of the last (K'th) iteration.

The image 6001 is virtually segments to segments 6000(i,k). The segments may be of the same shape and size but this is not necessarily so.

Outcome 6013 may be a tensor that includes a vector of values per each segment of the media unit. One or more objects may appear in a certain segment. For each object—an object identifier (of the signature) points to locations of significant values, within a certain vector associated with the certain segment.

For example—a top left segment (6001(1,1)) of the image may be represented in the outcome 6013 by a vector V(1,1) 6017(1,1) that has multiple values. The number of values per vector may exceed 100, 200, 500, 1000, and the like.

The significant values (for example—more than 10, 20, 30, 40 values, and/or more than 0.1%, 0.2%. 0.5%, 1%, 5% of all values of the vector and the like) may be selected. The significant values may have the values—but may be selected in any other manner.

FIG. 1B illustrates a set of significant responses 6015(1,1) of vector V(1,1) 6017(1,1). The set includes five significant values (such as first significant value SV1(1,1) 6013(1,1,1), second significant value SV2(1,1), third significant value SV3(1,1), fourth significant value SV4(1,1), and fifth significant value SV5(1,1) 6013(1,1,5).

The image signature 6027 includes five indexes for the retrieval of the five significant values—first till fifth identifiers ID1-ID5 are indexes for retrieving the first till fifth significant values.

FIG. 1C illustrates a k'th iteration expansion process.

The k'th iteration expansion process start by receiving the merge results 5060′ of a previous iteration.

The merge results of a previous iteration may include values are indicative of previous expansion processes—for example—may include values that are indicative of relevant spanning elements from a previous expansion operation, values indicative of relevant regions of interest in a multidimensional representation of the merge results of a previous iteration.

The merge results (of the previous iteration) are fed to spanning elements such as spanning elements 5061(1)-5061(J).

Each spanning element is associated with a unique set of values. The set may include one or more values. The spanning elements apply different functions that may be orthogonal to each other. Using non-orthogonal functions may increase the number of spanning elements—but this increment may be tolerable.

The spanning elements may apply functions that are decorrelated to each other—even if not orthogonal to each other.

The spanning elements may be associated with different combinations of object identifiers that may “cover” multiple possible media units. Candidates for combinations of object identifiers may be selected in various manners—for example based on their occurrence in various images (such as test images) randomly, pseudo randomly, according to some rules and the like. Out of these candidates the combinations may be selected to be decorrelated, to cover said multiple possible media units and/or in a manner that certain objects are mapped to the same spanning elements.

Each spanning element compares the values of the merge results to the unique set (associated with the spanning element) and if there is a match—then the spanning element is deemed to be relevant. If so—the spanning element completes the expansion operation.

If there is no match—the spanning element is deemed to be irrelevant and enters a low power mode. The low power mode may also be referred to as an idle mode, a standby mode, and the like. The low power mode is termed low power because the power consumption of an irrelevant spanning element is lower than the power consumption of a relevant spanning element.

In FIG. 1C various spanning elements are relevant (5061(1)-5061(3)) and one spanning element is irrelevant (5061(J)).

Each relevant spanning element may perform a spanning operation that includes assigning an output value that is indicative of an identity of the relevant spanning elements of the iteration. The output value may also be indicative of identities of previous relevant spanning elements (from previous iterations).

For example—assuming that spanning element number fifty is relevant and is associated with a unique set of values of eight and four—then the output value may reflect the numbers fifty, four and eight—for example one thousand multiplied by (fifty+forty) plus forty. Any other mapping function may be applied.

FIG. 1C also illustrates the steps executed by each spanning element:

-   -   Checking if the merge results are relevant to the spanning         element (step 5091).     -   If-so—completing the spanning operation (step 5093).     -   If not—entering an idle state (step 5092).

FIG. 1D is an example of various merge operations.

A merge operation may include finding regions of interest. The regions of interest are regions within a multidimensional representation of the sensed information. A region of interest may exhibit a more significant response (for example a stronger, higher intensity response).

The merge operation (executed during a k'th iteration merge operation) may include at least one of the following:

-   -   Step 5031 of searching for overlaps between regions of interest         (of the k'th iteration expansion operation results) and define         regions of interest that are related to the overlaps.     -   Step 5032 of determining to drop one or more region of interest,         and dropping according to the determination.     -   Step 5033 of searching for relationships between regions of         interest (of the k'th iteration expansion operation results) and         define regions of interest that are related to the relationship.     -   Step 5034 of searching for proximate regions of interest (of the         k'th iteration expansion operation results) and define regions         of interest that are related to the proximity. Proximate may be         a distance that is a certain fraction (for example less than 1%)         of the multi-dimensional space, may be a certain fraction of at         least one of the regions of interest that are tested for         proximity.     -   Step 5035 of searching for relationships between regions of         interest (of the k'th iteration expansion operation results) and         define regions of interest that are related to the relationship.     -   Step 5036 of merging and/or dropping k'th iteration regions of         interest based on shape information related to shape of the k'th         iteration regions of interest.

The same merge operations may applied in different iterations.

Alternatively, different merge operations may be executed during different iterations.

FIG. 1E illustrates an example of a hybrid process and an input image 6001.

The hybrid process is hybrid in the sense that some expansion and merge operations are executed by a convolutional neural network (CNN) and some expansion and merge operations (denoted additional iterations of expansion and merge) are not executed by the CNN—but rather by a process that may include determining a relevancy of spanning elements and entering irrelevant spanning elements to a low power mode.

In FIG. 1E one or more initial iterations are executed by first and second CNN layers 6010(1) and 6010(2) that apply first and second functions 6015(1) and 6015(2).

The output of these layers provided information about image properties. The image properties may not amount to object detection. Image properties may include location of edges, properties of curves, and the like.

The CNN may include additional layers (for example third till N'th layer 6010(N)) that may provide a CNN output 6018 that may include object detection information. It should be noted that the additional layers may not be included.

It should be noted that executing the entire signature generation process by a hardware CNN of fixed connectivity may have a higher power consumption—as the CNN will not be able to reduce the power consumption of irrelevant nodes.

FIG. 1F illustrates an input image 6001, and a single iteration of an expansion operation and a merge operation.

In FIG. 1F the input image 6001 undergoes two expansion operations.

The first expansion operation involves filtering the input image by a first filtering operation 6031 to provide first regions of interest (denoted 1) in a first filtered image 6031′.

The first expansion operation also involves filtering the input image by a second filtering operation 6032 to provide first regions of interest (denoted 2) in a second filtered image 6032′,

The merge operation includes merging the two images by overlaying the first filtered image on the second filtered image to provide regions of interest 1, 2, 12 and 21. Region of interest 12 is an overlap area shared by a certain region of interest 1 and a certain region of interest 2. Region of interest 21 is a union of another region of interest 1 and another region of interest 2.

FIG. 1G illustrates method 5200 for generating a signature.

Method 5200 may include the following sequence of steps:

-   -   Step 5210 of receiving or generating an image.     -   Step 5220 of performing a first iteration expansion operation         (which is an expansion operation that is executed during a first         iteration)     -   Step 5230 of performing a first iteration merge operation.     -   Step 5240 of amending index k (k is an iteration counter). In         FIG. 7 in incremented by one—this is only an example of how the         number of iterations are tracked.     -   Step 5260 of performing a k'th iteration expansion operation on         the (k−1)'th iteration merge results.     -   Step 5270 of performing a k'th iteration merge operation (on the         k'th iteration expansion operation results.     -   Step 5280 of changing the value of index k.     -   Step 5290 of checking if all iteration ended (k reached its         final value—for example K).

If no—there are still iterations to be executed—jumping from step 5290 to step 5260.

If yes—jumping to step 5060 of completing the generation of the signature. This may include, for example, selecting significant attributes, determining retrieval information (for example indexes) that point to the selected significant attributes.

Step 5220 may include:

-   -   Step 5222 of generating multiple representations of the image         within a multi-dimensional space of f(1) dimensions. The         expansion operation of step 5220 generates a first iteration         multidimensional representation of the first image. The number         of dimensions of this first iteration multidimensional         representation is denoted f(1).     -   Step 5224 of assigning a unique index for each region of         interest within the multiple representations. For example,         referring to FIG. 6—indexes 1 and indexes 2 are assigned to         regions of interests generated during the first iteration         expansion operations 6031 and 6032.

Step 5230 may include:

-   -   Step 5232 of searching for relationships between regions of         interest and define regions of interest that are related to the         relationships. For example—union or intersection illustrate din         FIG. 6.     -   Step 5234 of assigning a unique index for each region of         interest within the multiple representations. For         example—referring to FIG. 6—indexes 1, 2, 12 and 21.

Step 5260 may include:

-   -   Step 5262 of generating multiple representations of the merge         results of the (k−1)'th iteration within a multi-dimensional         space of f(k) dimensions. The expansion operation of step 5260         generates a k'th iteration multidimensional representation of         the first image. The number of dimensions of this kth iteration         multidimensional representation is denoted f(k).     -   Step 5264 of assigning a unique index for each region of         interest within the multiple representations.

Step 5270 may include

-   -   Step 5272 of searching for relationships between regions of         interest and define regions of interest that are related to the         relationships.     -   Step 5274 of Assigning a unique index for each region of         interest within the multiple representations.

FIG. 1H illustrates a method 5201. In method 5201 the relationships between the regions of interest are overlaps.

Thus—step 5232 is replaced by step 5232′ of searching for overlaps between regions of interest and define regions of interest that are related to the overlaps.

Step 5272 is replaced by step 5272′ of searching for overlaps between regions of interest and define regions of interest that are related to the overlaps.

FIG. 1I illustrates a method 7000 for low-power calculation of a signature.

Method 7000 starts by step 7010 of receiving or generating a media unit of multiple objects.

Step 7010 may be followed by step 7012 of processing the media unit by performing multiple iterations, wherein at least some of the multiple iterations comprises applying, by spanning elements of the iteration, dimension expansion process that are followed by a merge operation.

The applying of the dimension expansion process of an iteration may include (a) determining a relevancy of the spanning elements of the iteration; and (b) completing the dimension expansion process by relevant spanning elements of the iteration and reducing a power consumption of irrelevant spanning elements until, at least, a completion of the applying of the dimension expansion process.

The identifiers may be retrieval information for retrieving the significant portions.

The at least some of the multiple iterations may be a majority of the multiple iterations.

The output of the multiple iteration may include multiple property attributes for each segment out of multiple segments of the media unit; and wherein the significant portions of an output of the multiple iterations may include more impactful property attributes.

The first iteration of the multiple iteration may include applying the dimension expansion process by applying different filters on the media unit.

The at least some of the multiple iteration exclude at least a first iteration of the multiple iterations. See, for example, FIG. 1E.

The determining the relevancy of the spanning elements of the iteration may be based on at least some identities of relevant spanning elements of at least one previous iteration.

The determining the relevancy of the spanning elements of the iteration may be based on at least some identities of relevant spanning elements of at least one previous iteration that preceded the iteration.

The determining the relevancy of the spanning elements of the iteration may be based on properties of the media unit.

The determining the relevancy of the spanning elements of the iteration may be performed by the spanning elements of the iteration.

Method 7000 may include a neural network processing operation that may be executed by one or more layers of a neural network and does not belong to the at least some of the multiple iterations. See, for example, FIG. 1E.

The at least one iteration may be executed without reducing power consumption of irrelevant neurons of the one or more layers.

The one or more layers may output information about properties of the media unit, wherein the information differs from a recognition of the multiple objects.

The applying, by spanning elements of an iteration that differs from the first iteration, the dimension expansion process may include assigning output values that may be indicative of an identity of the relevant spanning elements of the iteration. See, for example, FIG. 1C.

The applying, by spanning elements of an iteration that differs from the first iteration, the dimension expansion process may include assigning output values that may be indicative a history of dimension expansion processes until the iteration that differs from the first iteration.

The each spanning element may be associated with a subset of reference identifiers. The determining of the relevancy of each spanning elements of the iteration may be based a relationship between the subset of the reference identifiers of the spanning element and an output of a last merge operation before the iteration.

The output of a dimension expansion process of an iteration may be a multidimensional representation of the media unit that may include media unit regions of interest that may be associated with one or more expansion processes that generated the regions of interest.

The merge operation of the iteration may include selecting a subgroup of media unit regions of interest based on a spatial relationship between the subgroup of multidimensional regions of interest. See, for example, FIGS. 3 and 6.

Method 7000 may include applying a merge function on the subgroup of multidimensional regions of interest. See, for example, FIGS. 1C and 1F.

Method 7000 may include applying an intersection function on the subgroup of multidimensional regions of interest. See, for example, FIGS. 1C and 1F.

The merge operation of the iteration may be based on an actual size of one or more multidimensional regions of interest.

The merge operation of the iteration may be based on relationship between sizes of the multidimensional regions of interest. For example—larger multidimensional regions of interest may be maintained while smaller multidimensional regions of interest may be ignored of.

The merge operation of the iteration may be based on changes of the media unit regions of interest during at least the iteration and one or more previous iteration.

Step 7012 may be followed by step 7014 of determining identifiers that are associated with significant portions of an output of the multiple iterations.

Step 7014 may be followed by step 7016 of providing a signature that comprises the identifiers and represents the multiple objects.

Localization and Segmentation

Any of the mentioned above signature generation method provides a signature that does not explicitly includes accurate shape information. This adds to the robustness of the signature to shape related inaccuracies or to other shape related parameters.

The signature includes identifiers for identifying media regions of interest.

Each media region of interest may represent an object (for example a vehicle, a pedestrian, a road element, a human made structure, wearables, shoes, a natural element such as a tree, the sky, the sun, and the like) or a part of an object (for example—in the case of the pedestrian—a neck, a head, an arm, a leg, a thigh, a hip, a foot, an upper arm, a forearm, a wrist, and a hand). It should be noted that for object detection purposes a part of an object may be regarded as an object.

The exact shape of the object may be of interest.

FIG. 1J illustrates method 7002 of generating a hybrid representation of a media unit.

Method 7002 may include a sequence of steps 7020, 7022, 7024 and 7026.

Step 7020 may include receiving or generating the media unit.

Step 7022 may include processing the media unit by performing multiple iterations, wherein at least some of the multiple iterations comprises applying, by spanning elements of the iteration, dimension expansion process that are followed by a merge operation.

Step 7024 may include selecting, based on an output of the multiple iterations, media unit regions of interest that contributed to the output of the multiple iterations.

Step 7026 may include providing a hybrid representation, wherein the hybrid representation may include (a) shape information regarding shapes of the media unit regions of interest, and (b) a media unit signature that includes identifiers that identify the media unit regions of interest.

Step 7024 may include selecting the media regions of interest per segment out of multiple segments of the media unit. See, for example, FIG. 2.

Step 7026 may include step 7027 of generating the shape information.

The shape information may include polygons that represent shapes that substantially bound the media unit regions of interest. These polygons may be of a high degree.

In order to save storage space, the method may include step 7028 of compressing the shape information of the media unit to provide compressed shape information of the media unit.

FIG. 1K illustrates method 5002 for generating a hybrid representation of a media unit.

Method 5002 may start by step 5011 of receiving or generating a media unit.

Step 5011 may be followed by processing the media unit by performing multiple iterations, wherein at least some of the multiple iterations comprises applying, by spanning elements of the iteration, dimension expansion process that are followed by a merge operation.

The processing may be followed by steps 5060 and 5062.

The processing may include steps 5020, 5030, 5040 and 5050.

Step 5020 may include performing a k'th iteration expansion process (k may be a variable that is used to track the number of iterations).

Step 5030 may include performing a k'th iteration merge process.

Step 5040 may include changing the value of k.

Step 5050 may include checking if all required iterations were done—if so proceeding to steps 5060 and 5062. Else—jumping to step 5020.

The output of step 5020 is a k'th iteration expansion result.

The output of step 5030 is a k'th iteration merge result.

For each iteration (except the first iteration)—the merge result of the previous iteration is an input to the current iteration expansion process.

Step 5060 may include completing the generation of the signature.

Step 5062 may include generating shape information regarding shapes of media unit regions of interest. The signature and the shape information provide a hybrid representation of the media unit.

The combination of steps 5060 and 5062 amounts to a providing a hybrid representation, wherein the hybrid representation may include (a) shape information regarding shapes of the media unit regions of interest, and (b) a media unit signature that includes identifiers that identify the media unit regions of interest.

FIG. 1L illustrates method 5203 for generating a hybrid representation of an image.

Method 5200 may include the following sequence of steps:

-   -   Step 5210 of receiving or generating an image.     -   Step 5230 of performing a first iteration expansion operation         (which is an expansion operation that is executed during a first         iteration)     -   Step 5240 of performing a first iteration merge operation.     -   Step 5240 of amending index k (k is an iteration counter). In         FIG. 1L in incremented by one—this is only an example of how the         number of iterations are tracked.     -   Step 5260 of performing a k'th iteration expansion operation on         the (k−1)'th iteration merge results.     -   Step 5270 of Performing a k'th iteration merge operation (on the         k'th iteration expansion operation results.     -   Step 5280 of changing the value of index k.     -   Step 5290 of checking if all iteration ended (k reached its         final value—for example K).

If no—there are still iterations to be executed—jumping from step 5290 to step 5260.

If yes—jumping to step 5060.

Step 5060 may include completing the generation of the signature. This may include, for example, selecting significant attributes, determining retrieval information (for example indexes) that point to the selected significant attributes.

Step 5062 may include generating shape information regarding shapes of media unit regions of interest. The signature and the shape information provide a hybrid representation of the media unit.

The combination of steps 5060 and 5062 amounts to a providing a hybrid representation, wherein the hybrid representation may include (a) shape information regarding shapes of the media unit regions of interest, and (b) a media unit signature that includes identifiers that identify the media unit regions of interest.

Step 5220 may include:

-   -   Step 5222 of generating multiple representations of the image         within a multi-dimensional space of f(k) dimensions.     -   Step 5224 of assigning a unique index for each region of         interest within the multiple representations. (for example,         referring to FIG. 1F—indexes 1 and indexes 2 following first         iteration expansion operations 6031 and 6032.

Step 5230 may include

-   -   Step 5226 of searching for relationships between regions of         interest and define regions of interest that are related to the         relationships. For example—union or intersection illustrated in         FIG. 1F.     -   Step 5228 of assigning a unique index for each region of         interest within the multiple representations. For         example—referring to FIG. 1F—indexes 1, 2, 12 and 21.

Step 5260 may include:

-   -   Step 5262 of generating multiple representations of the merge         results of the (k−1)'th iteration within a multi-dimensional         space of f(k) dimensions. The expansion operation of step 5260         generates a k'th iteration multidimensional representation of         the first image. The number of dimensions of this kth iteration         multidimensional representation is denoted f(k).     -   Step 5264 of assigning a unique index for each region of         interest within the multiple representations.

Step 5270 may include

-   -   Step 5272 of searching for relationships between regions of         interest and define regions of interest that are related to the         relationships.     -   Step 5274 of assigning a unique index for each region of         interest within the multiple representations.

FIG. 1M illustrates method 5205 for generating a hybrid representation of an image.

Method 5200 may include the following sequence of steps:

-   -   Step 5210 of receiving or generating an image.     -   Step 5230 of performing a first iteration expansion operation         (which is an expansion operation that is executed during a first         iteration)     -   Step 5240 of performing a first iteration merge operation.     -   Step 5240 of amending index k (k is an iteration counter). In         FIG. 1M in incremented by one—this is only an example of how the         number of iterations are tracked.     -   Step 5260 of performing a k'th iteration expansion operation on         the (k−1)'th iteration merge results.     -   Step 5270 of performing a k'th iteration merge operation (on the         k'th iteration expansion operation results.     -   Step 5280 of changing the value of index k.     -   Step 5290 of checking if all iteration ended (k reached its         final value—for example K).

If no—there are still iterations to be executed—jumping from step 5290 to step 5260.

If yes—jumping to steps 5060 and 5062.

Step 5060 may include completing the generation of the signature. This may include, for example, selecting significant attributes, determining retrieval information (for example indexes) that point to the selected significant attributes.

Step 5062 may include generating shape information regarding shapes of media unit regions of interest. The signature and the shape information provide a hybrid representation of the media unit.

The combination of steps 5060 and 5062 amounts to a providing a hybrid representation, wherein the hybrid representation may include (a) shape information regarding shapes of the media unit regions of interest, and (b) a media unit signature that includes identifiers that identify the media unit regions of interest.

Step 5220 may include:

-   -   Step 5221 of filtering the image with multiple filters that are         orthogonal to each other to provide multiple filtered images         that are representations of the image in a multi-dimensional         space of f(1) dimensions. The expansion operation of step 5220         generates a first iteration multidimensional representation of         the first image. The number of filters is denoted f(1).     -   Step 5224 of assigning a unique index for each region of         interest within the multiple representations. (for example,         referring to FIG. 1F—indexes 1 and indexes 2 following first         iteration expansion operations 6031 and 6032.

Step 5230 may include

-   -   Step 5226 of searching for relationships between regions of         interest and define regions of interest that are related to the         relationships. For example—union or intersection illustrated in         FIG. 1F.     -   Step 5228 of assigning a unique index for each region of         interest within the multiple representations. For         example—referring to FIG. 1F—indexes 1, 2, 12 and 21.

Step 5260 may include:

-   -   Step 5262 of generating multiple representations of the merge         results of the (k−1)'th iteration within a multi-dimensional         space of f(k) dimensions. The expansion operation of step 5260         generates a k'th iteration multidimensional representation of         the first image. The number of dimensions of this kth iteration         multidimensional representation is denoted f(k).     -   Step 5264 of assigning a unique index for each region of         interest within the multiple representations.

Step 5270 may include

-   -   Step 5272 of searching for relationships between regions of         interest and define regions of interest that are related to the         relationships.     -   Step 5274 of assigning a unique index for each region of         interest within the multiple representations.

The filters may be orthogonal may be non-orthogonal—for example be decorrelated. Using non-orthogonal filters may increase the number of filters—but this increment may be tolerable.

Object Detection Using Compressed Shape Information

Object detection may include comparing a signature of an input image to signatures of one or more cluster structures in order to find one or more cluster structures that include one or more matching signatures that match the signature of the input image.

The number of input images that are compared to the cluster structures may well exceed the number of signatures of the cluster structures. For example—thousands, tens of thousands, hundreds of thousands (and even more) of input signature may be compared to much less cluster structure signatures. The ratio between the number of input images to the aggregate number of signatures of all the cluster structures may exceed ten, one hundred, one thousand, and the like.

In order to save computational resources, the shape information of the input images may be compressed.

On the other hand—the shape information of signatures that belong to the cluster structures may be uncompressed—and of higher accuracy than those of the compressed shape information.

When the higher quality is not required—the shape information of the cluster signature may also be compressed.

Compression of the shape information of cluster signatures may be based on a priority of the cluster signature, a popularity of matches to the cluster signatures, and the like.

The shape information related to an input image that matches one or more of the cluster structures may be calculated based on shape information related to matching signatures.

For example—a shape information regarding a certain identifier within the signature of the input image may be determined based on shape information related to the certain identifiers within the matching signatures.

Any operation on the shape information related to the certain identifiers within the matching signatures may be applied in order to determine the (higher accuracy) shape information of a region of interest of the input image identified by the certain identifier.

For example—the shapes may be virtually overlaid on each other and the population per pixel may define the shape.

For example—only pixels that appear in at least a majority of the overlaid shaped should be regarded as belonging to the region of interest.

Other operations may include smoothing the overlaid shapes, selecting pixels that appear in all overlaid shapes.

The compressed shape information may be ignored of or be taken into account.

FIG. 1N illustrates method 7003 of determining shape information of a region of interest of a media unit.

Method 7003 may include a sequence of steps 7030, 7032 and 7034.

Step 7030 may include receiving or generating a hybrid representation of a media unit. The hybrid representation includes compressed shape information.

Step 7032 may include comparing the media unit signature of the media unit to signatures of multiple concept structures to find a matching concept structure that has at least one matching signature that matches to the media unit signature.

Step 7034 may include calculating higher accuracy shape information that is related to regions of interest of the media unit, wherein the higher accuracy shape information is of higher accuracy than the compressed shape information of the media unit, wherein the calculating is based on shape information associated with at least some of the matching signatures.

Step 7034 may include at least one out of:

-   -   Determining shapes of the media unit regions of interest using         the higher accuracy shape information.     -   For each media unit region of interest, virtually overlaying         shapes of corresponding media units of interest of at least some         of the matching signatures.

FIG. 1O illustrates a matching process and a generation of a higher accuracy shape information.

It is assumed that there are multiple (M) cluster structures 4974(1)-4974(M). Each cluster structure includes cluster signatures, metadata regarding the cluster signatures, and shape information regarding the regions of interest identified by identifiers of the cluster signatures.

For example—first cluster structure 4974(1) includes multiple (N1) signatures (referred to as cluster signatures CS) CS(1,1)-CS(1,N1) 4975(1,1)-4975(1,N1), metadata 4976(1), and shape information (Shapeinfo 4977(1)) regarding shapes of regions of interest associated with identifiers of the CSs.

Yet for another example—M'th cluster structure 4974(M) includes multiple (N2) signatures (referred to as cluster signatures CS) CS(M,1)-CS(M,N2) 4975(M,1)-4975(M,N2), metadata 4976(M), and shape information (Shapeinfo 4977(M)) regarding shapes of regions of interest associated with identifiers of the CSs.

The number of signatures per concept structure may change over time—for example due to cluster reduction attempts during which a CS is removed from the structure to provide a reduced cluster structure, the reduced structure structure is checked to determine that the reduced cluster signature may still identify objects that were associated with the (non-reduced) cluster signature—and if so the signature may be reduced from the cluster signature.

The signatures of each cluster structures are associated to each other, wherein the association may be based on similarity of signatures and/or based on association between metadata of the signatures.

Assuming that each cluster structure is associated with a unique object—then objects of a media unit may be identified by finding cluster structures that are associated with said objects. The finding of the matching cluster structures may include comparing a signature of the media unit to signatures of the cluster structures- and searching for one or more matching signature out of the cluster signatures.

In FIG. 1O—a media unit having a hybrid representation undergoes object detection. The hybrid representation includes media unit signature 4972 and compressed shape information 4973.

The media unit signature 4972 is compared to the signatures of the M cluster structures—from CS(1,1) 4975(1,1) till CS(M,N2) 4975(M,N2).

We assume that one or more cluster structures are matching cluster structures.

Once the matching cluster structures are found the method proceeds by generating shape information that is of higher accuracy then the compressed shape information.

The generation of the shape information is done per identifier.

For each j that ranges between 1 and J (J is the number of identifiers per the media unit signature 4972) the method may perform the steps of:

-   -   Find (step 4978(j)) the shape information of the j'th identifier         of each matching signature- or of each signature of the matching         cluster structure.     -   Generate (step 4979(j)) a higher accuracy shape information of         the j'th identifier.

For example—assuming that the matching signatures include CS(1,1) 2975(1,1), CS(2,5) 2975(2,5), CS(7,3) 2975(7,3) and CS(15,2) 2975(15,2), and that the j'th identifier is included in CS(1,1) 2975(1,1),CS(7,3) 2975(7,3) and CS(15,2) 2975(15,2)—then the shape information of the j'th identifier of the media unit is determined based on the shape information associated with CS(1,1) 2975(1,1),CS(7,3) 2975(7,3) and CS(15,2) 2975(15,2).

FIG. 1P illustrates an image 8000 that includes four regions of interest 8001, 8002, 8003 and 8004. The signature 8010 of image 8000 includes various identifiers including ID1 8011, ID2 8012, ID3 8013 and ID4 8014 that identify the four regions of interest 8001, 8002, 8003 and 8004.

The shapes of the four regions of interest 8001, 8002, 8003 and 8004 are four polygons. Accurate shape information regarding the shapes of these regions of interest may be generated during the generation of signature 8010.

FIG. 1Q illustrates the compressing of the shape information to represent a compressed shape information that reflects simpler approximations (8001′, 8002′, 8003′ and 8004′) of the regions of interest 8001, 8002, 8003 and 8004. In this example simpler may include less facets, fewer values of angles, and the like.

The hybrid representation of the media unit, after compression represent an media unit with simplified regions of interest 8001′, 8002′, 8003′ and 8004′—as shown in FIG. 1R.

Scale Based Bootstrap

Objects may appear in an image at different scales. Scale invariant object detection may improve the reliability and repeatability of the object detection and may also use fewer number of cluster structures—thus reduced memory resources and also lower computational resources required to maintain fewer cluster structures.

FIG. 1S illustrates method 8020 for scale invariant object detection.

Method 8020 may include a first sequence of steps that may include step 8022, 8024, 8026 and 8028.

Step 8022 may include receiving or generating a first image in which an object appears in a first scale and a second image in which the object appears in a second scale that differs from the first scale.

Step 8024 may include generating a first image signature and a second image signature.

The first image signature includes a first group of at least one certain first image identifier that identifies at least a part of the object. See, for example image 8000′ of FIG. 2A. The person is identified by identifiers ID6 8016 and ID8 8018 that represent regions of interest 8006 and 8008.

The second image signature includes a second group of certain second image identifiers that identify different parts of the object.

See, for example image 8000 of FIG. 19. The person is identified by identifiers ID1 8011, ID2 8012, ID3 8013, and ID4 8014 that represent regions of interest 8001, 8002, 8003 and 8004.

The second group is larger than first group—as the second group has more members than the first group.

Step 8026 may include linking between the at least one certain first image identifier and the certain second image identifiers.

Step 8026 may include linking between the first image signature, the second image signature and the object.

Step 8026 may include adding the first signature and the second signature to a certain concept structure that is associated with the object. For example, referring to FIG. 1O, the signatures of the first and second images may be included in a cluster concept out of 4974(1)-4974(M).

Step 8028 may include determining whether an input image includes the object based, at least in part, on the linking. The input image differs from the first and second images.

The determining may include determining that the input image includes the object when a signature of the input image includes the at least one certain first image identifier or the certain second image identifiers.

The determining may include determining that the input image includes the object when the signature of the input image includes only a part of the at least one certain first image identifier or only a part of the certain second image identifiers.

The linking may be performed for more than two images in which the object appears in more than two scales.

For example, see FIG. 2B in which a person appears at three different scales—at three different images.

In first image 8051 the person is included in a single region of interest 8061 and the signature 8051′ of first image 8051 includes an identifier ID61 that identifies the single region of interest—identifies the person.

In second image 8052 the upper part of the person is included in region of interest 8068, the lower part of the person is included in region of interest 8069 and the signature 8052′ of second image 8052 includes identifiers ID68 and ID69 that identify regions of interest 8068 and 8069 respectively.

In third image 8053 the eyes of the person are included in region of interest 8062, the mouth of the person is included in region of interest 8063, the head of the person appears in region of interest 8064, the neck and arms of the person appear in region of interest 8065, the middle part of the person appears in region of interest 8066, and the lower part of the person appears in region of interest 8067. Signature 8053′ of third image 8053 includes identifiers ID62, ID63, ID64, ID65, ID55 and ID67 that identify regions of interest 8062-8067 respectively.

Method 8020 may link signatures 8051′, 8052′ and 8053′ to each other. For example—these signatures may be included in the same cluster structure.

Method 8020 may link (i) ID61, (ii) signatures ID68 and ID69, and (ii) signature ID62, ID63, ID64, ID65, ID66 and ID67.

FIG. 2C illustrates method 8030 for object detection.

Method 8030 may include the steps of method 8020 or may be preceded by steps 8022, 8024 and 8026.

Method 8030 may include a sequence of steps 8032, 8034, 8036 and 8038.

Step 8032 may include receiving or generating an input image.

Step 8034 may include generating a signature of the input image.

Step 8036 may include comparing the signature of the input image to signatures of a certain concept structure. The certain concept structure may be generated by method 8020.

Step 8038 may include determining that the input image comprises the object when at least one of the signatures of the certain concept structure matches the signature of the input image.

FIG. 2D illustrates method 8040 for object detection.

Method 8040 may include the steps of method 8020 or may be preceded by steps 8022, 8024 and 8026.

Method 8040 may include a sequence of steps 8041, 8043, 8045, 8047 and 8049.

Step 8041 may include receiving or generating an input image.

Step 8043 may include generating a signature of the input image, the signature of the input image comprises only some of the certain second image identifiers; wherein the input image of the second scale.

Step 8045 may include changing a scale of the input image to the first scale to a provide an amended input image.

Step 8047 may include generating a signature of the amended input image.

Step 8049 may include verifying that the input image comprises the object when the signature of the amended input image comprises the at least one certain first image identifier.

FIG. 2E illustrates method 8050 for object detection.

Method 8050 may include the steps of method 8020 or may be preceded by steps 8022, 8024 and 8026.

Method 8050 may include a sequence of steps 8052, 8054, 8056 and 8058.

Step 8052 may include receiving or generating an input image.

Step 8054 may include generating a signature of the input image.

Step 8056 may include searching in the signature of the input image for at least one of (a) the at least one certain first image identifier, and (b) the certain second image identifiers.

Step 8058 may include determining that the input image comprises the object when the signature of the input image comprises the at least one of (a) the at least one certain first image identifier, and (b) the certain second image identifiers.

It should be noted that step 8056 may include searching in the signature of the input image for at least one of (a) one or more certain first image identifier of the at least one certain first image identifier, and (b) at least one certain second image identifier of the certain second image identifiers.

It should be noted that step 8058 may include determining that the input image includes the object when the signature of the input image comprises the at least one of (a) one or more certain first image identifier of the at least one certain first image identifier, and (b) the at least one certain second image identifier.

Movement Based Bootstrapping

A single object may include multiple parts that are identified by different identifiers of a signature of the image. In cases such as unsupervised learning, it may be beneficial to link the multiple object parts to each other without receiving prior knowledge regarding their inclusion in the object.

Additionally or alternatively, the linking can be done in order to verify a previous linking between the multiple object parts.

FIG. 2F illustrates method 8070 for object detection.

Method 8070 is for movement based object detection.

Method 8070 may include a sequence of steps 8071, 8073, 8075, 8077, 8078 and 8079.

Step 8071 may include receiving or generating a video stream that includes a sequence of images.

Step 8073 may include generating image signatures of the images. Each image is associated with an image signature that comprises identifiers. Each identifier identifiers a region of interest within the image.

Step 8075 may include generating movement information indicative of movements of the regions of interest within consecutive images of the sequence of images. Step 8075 may be preceded by or may include generating or receiving location information indicative of a location of each region of interest within each image. The generating of the movement information is based on the location information.

Step 8077 may include searching, based on the movement information, for a first group of regions of interest that follow a first movement. Different first regions of interest are associated with different parts of an object.

Step 8078 may include linking between first identifiers that identify the first group of regions of interest.

Step 8079 may include linking between first image signatures that include the first linked identifiers.

Step 8079 may include adding the first image signatures to a first concept structure, the first concept structure is associated with the first image.

Step 8079 may be followed by determining whether an input image includes the object based, at least in part, on the linking.

An example of various steps of method 8070 is illustrated in FIG. 2H.

FIG. 2G illustrates three images 8091, 8092 and 8093 that were taken at different points in time.

First image 8091 illustrates a gate 8089′ that is located in region of interest 8089 and a person that faces the gate. Various parts of the person are located within regions of interest 8081, 8082, 8083, 8084 and 8085.

The first image signature 8091′ includes identifiers ID81, ID82, ID83, ID84, ID85 and ID89 that identify regions of interest 8081, 8082, 8083, 8084, 8085 and 8089 respectively.

The first image location information 8091″ includes the locations L81, L82, L83, L84, L85 and L89 of regions of interest 8081, 8082, 8083, 8084, 8085 and 8089 respectively. A location of a region of interest may include a location of the center of the region of interest, the location of the borders of the region of interest or any location information that may define the location of the region of interest or a part of the region of interest.

Second image 8092 illustrates a gate that is located in region of interest 8089 and a person that faces the gate. Various parts of the person are located within regions of interest 8081, 8082, 8083, 8084 and 8085. Second image also includes a pole that is located within region of interest 8086. In the first image that the pole was concealed by the person.

The second image signature 8092′ includes identifiers ID81, ID82, ID83, ID84, ID85, ID86, and ID89 that identify regions of interest 8081, 8082, 8083, 8084, 8085, 8086 and 8089 respectively.

The second image location information 8092″ includes the locations L81, L82, L83, L84, L85, L86 and L89 of regions of interest 8081, 8082, 8083, 8084, 8085, 8086 and 8089 respectively.

Third image 8093 illustrates a gate that is located in region of interest 8089 and a person that faces the gate. Various parts of the person are located within regions of interest 8081, 8082, 8083, 8084 and 8085. Third image also includes a pole that is located within region of interest 8086, and a balloon that is located within region of interest 8087.

The third image signature 8093′ includes identifiers ID81, ID82, ID83, ID84, ID85, ID86, ID87 and ID89 that identify regions of interest 8081, 8082, 8083, 8084, 8085, 8086, 8087 and 8089 respectively.

The third image location information 8093″ includes the locations L81, L82, L83, L84, L85, L86, L87 and L89 of regions of interest 8081, 8082, 8083, 8084, 8085, 8086, 8086 and 8089 respectively.

The motion of the various regions of interest may be calculated by comparing the location information related to different images. The movement information may take into account the different in the acquisition time of the images.

The comparison shows that regions of interest 8081, 8082, 8083, 8084, 8085 move together and thus they should be linked to each other—and it may be assumed that they all belong to the same object.

FIG. 2H illustrates method 8100 for object detection.

Method 8100 may include the steps of method 8070 or may be preceded by steps 8071, 8073, 8075, 8077 and 8078.

Method 8100 may include the following sequence of steps:

-   -   Step 8102 of receiving or generating an input image.     -   Step 8104 of generating a signature of the input image.     -   Step 8106 of comparing the signature of the input image to         signatures of a first concept structure. The first concept         structure includes first identifiers that were linked to each         other based on movements of first regions of interest that are         identified by the first identifiers.     -   Step 8108 of determining that the input image includes a first         object when at least one of the signatures of the first concept         structure matches the signature of the input image.

FIG. 2I illustrates method 8110 for object detection.

Method 8110 may include the steps of method 8070 or may be preceded by steps 8071, 8073, 8075, 8077 and 8078.

Method 8110 may include the following sequence of steps:

-   -   Step 8112 of receiving or generating an input image.     -   Step 8114 of generating a signature of the input image.     -   Step 8116 of searching in the signature of the input image for         at least one of the first identifiers.     -   Step 8118 of determining that the input image comprises the         object when the signature of the input image comprises at least         one of the first identifiers.

Object Detection that is Robust to Angle of Acquisition

Object detection may benefit from being robust to the angle of acquisition—to the angle between the optical axis of an image sensor and a certain part of the object. This allows the detection process to be more reliable, use fewer different clusters (may not require multiple clusters for identifying the same object from different images).

FIG. 2J illustrates method 8120 that includes the following steps:

-   -   Step 8122 of receiving or generating images of objects taken         from different angles.     -   Step 8124 of finding images of objects taken from different         angles that are close to each other. Close enough may be less         than 1, 5, 10, 15 and 20 degrees—but the closeness may be better         reflected by the reception of substantially the same signature.     -   Step 8126 of linking between the images of similar signatures.         This may include searching for local similarities. The         similarities are local in the sense that they are calculated per         a subset of signatures. For example—assuming that the similarity         is determined per two images—then a first signature may be         linked to a second signature that is similar to the first image.         A third signature may be linked to the second image based on the         similarity between the second and third signatures- and even         regardless of the relationship between the first and third         signatures.

Step 8126 may include generating a concept data structure that includes the similar signatures.

This so-called local or sliding window approach, in addition to the acquisition of enough images (that will statistically provide a large angular coverage) will enable to generate a concept structure that include signatures of an object taken at multiple directions.

FIG. 2K illustrates a person 8130 that is imaged from different angles (8131, 8132, 8133, 8134, 8135 and 8136). While the signature of a front view of the person (obtained from angle 8131) differs from the signature of the side view of the person (obtained from angle 8136), the signature of images taken from multiple angles between angles 8141 and 8136 compensates for the difference—as the difference between images obtained from close angles are similar (local similarity) to each other.

Signature Tailored Matching Threshold

Object detection may be implemented by (a) receiving or generating concept structures that include signatures of media units and related metadata, (b) receiving a new media unit, generating a new media unit signature, and (c) comparing the new media unit signature to the concept signatures of the concept structures.

The comparison may include comparing new media unit signature identifiers (identifiers of objects that appear in the new media unit) to concept signature identifiers and determining, based on a signature matching criteria whether the new media unit signature matches a concept signature. If such a match is found then the new media unit is regarded as including the object associated with that concept structure.

It was found that by applying an adjustable signature matching criteria, the matching process may be highly effective and may adapt itself to the statistics of appearance of identifiers in different scenarios. For example—a match may be obtained when a relatively rear but highly distinguishing identifier appears in the new media unit signature and in a cluster signature, but a mismatch may be declared when multiple common and slightly distinguishing identifiers appear in the new media unit signature and in a cluster signature.

FIG. 2L illustrates method 8200 for object detection.

Method 8200 may include:

-   -   Step 8210 of receiving an input image.     -   Step 8212 of generating a signature of the input image.     -   Step 8214 of comparing the signature of the input image to         signatures of a concept structure.     -   Step 8216 of determining whether the signature of the input         image matches any of the signatures of the concept structure         based on signature matching criteria, wherein each signature of         the concept structure is associated within a signature matching         criterion that is determined based on an object detection         parameter of the signature.     -   Step 8218 of concluding that the input image comprises an object         associated with the concept structure based on an outcome of the         determining.

The signature matching criteria may be a minimal number of matching identifiers that indicate of a match. For example—assuming a signature that include few tens of identifiers, the minimal number may vary between a single identifier to all of the identifiers of the signature.

It should be noted that an input image may include multiple objects and that an signature of the input image may match multiple cluster structures. Method 8200 is applicable to all of the matching processes- and that the signature matching criteria may be set for each signature of each cluster structure.

Step 8210 may be preceded by step 8202 of determining each signature matching criterion by evaluating object detection capabilities of the signature under different signature matching criteria.

Step 8202 may include:

-   -   Step 8203 of receiving or generating signatures of a group of         test images.     -   Step 8204 of calculating the object detection capability of the         signature, for each signature matching criterion of the         different signature matching criteria.     -   Step 8206 of selecting the signature matching criterion based on         the object detection capabilities of the signature under the         different signature matching criteria.

The object detection capability may reflect a percent of signatures of the group of test images that match the signature.

The selecting of the signature matching criterion comprises selecting the signature matching criterion that once applied results in a percent of signatures of the group of test images that match the signature that is closets to a predefined desired percent of signatures of the group of test images that match the signature.

The object detection capability may reflect a significant change in the percent of signatures of the group of test images that match the signature. For example—assuming, that the signature matching criteria is a minimal number of matching identifiers and that changing the value of the minimal numbers may change the percentage of matching test images. A substantial change in the percentage (for example a change of more than 10, 20, 30, 40 percent) may be indicative of the desired value. The desired value may be set before the substantial change, proximate to the substantial change, and the like.

For example, referring to FIG. 1O, cluster signatures CS(1,1), CS(2,5), CS(7,3) and CS(15,2) match unit signature 4972. Each of these matches may apply a unique signature matching criterion.

FIG. 2M illustrates method 8220 for object detection.

Method 8220 is for managing a concept structure.

Method 8220 may include:

-   -   Step 8222 of determining to add a new signature to the concept         structure. The concept structure may already include at least         one old signature. The new signature includes identifiers that         identify at least parts of objects.     -   Step 8224 of determining a new signature matching criterion that         is based on one or more of the identifiers of the new signature.         The new signature matching criterion determines when another         signature matches the new signature. The determining of the new         signature matching criterion may include evaluating object         detection capabilities of the signature under different         signature matching criteria.

Step 8224 may include steps 8203, 8204 and 8206 (include din step 8206) of method 8200.

Examples of Systems

FIG. 22N illustrates an example of a system capable of executing one or more of the mentioned above methods.

The system include various components, elements and/or units.

A component element and/or unit may be a processing circuitry may be implemented as a central processing unit (CPU), and/or one or more other integrated circuits such as application-specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), full-custom integrated circuits, etc., or a combination of such integrated circuits.

Alternatively, each component element and/or unit may implemented in hardware, firmware, or software that may be executed by a processing circuitry.

System 4900 may include sensing unit 4902, communication unit 4904, input 4911, processor 4950, and output 4919. The communication unit 4904 may include the input and/or the output.

Input and/or output may be any suitable communications component such as a network interface card, universal serial bus (USB) port, disk reader, modem or transceiver that may be operative to use protocols such as are known in the art to communicate either directly, or indirectly, with other elements of the system.

Processor 4950 may include at least some out of

-   -   Multiple spanning elements 4951(q).     -   Multiple merge elements 4952(r).     -   Object detector 4953.     -   Cluster manager 4954.     -   Controller 4955.     -   Selection unit 4956.     -   Object detection determination unit 4957.     -   Signature generator 4958.     -   Movement information unit 4959.     -   Identifier unit 4960.

There may be provided a method for scale invariant object detection, the method may include receiving or generating a first image in which an object appears in a first scale and a second image in which the object appears in a second scale that differs from the first scale; generating a first image signature and a second image signature; wherein the first image signature may include a first group of at least one certain first image identifier that identifies at least a part of the object; wherein the second image signature may include a second group of certain second image identifiers that identify different parts of the object; wherein the second group may be larger than first group; and linking between the at least one certain first image identifier and the certain second image identifiers.

There may be provided a method for movement based object detection, the method may include receiving or generating a video stream that may include a sequence of images; generating image signatures of the images; wherein each image may be associated with an image signature that may include identifiers; wherein each identifier identifiers a region of interest within the image; generating movement information indicative of movements of the regions of interest within consecutive images of the sequence of images; searching, based on the movement information, for a first group of regions of interest that follow a first movement; wherein different first regions of interest may be associated with different parts of an object; and linking between first identifiers that identify the first group of regions of interest.

The linking may include linking between first image signatures that include the first linked identifiers.

The linking may include adding the first image signatures to a first concept structure, the first concept structure may be associated with the first image.

The method may include receiving or generating an input image; generating a signature of the input image; comparing the signature of the input image to signatures of the first concept structure; and determining that the input image may include a first object when at least one of the signatures of the first concept structure matches the signature of the input image.

The method may include receiving or generating an input image; generating a signature of the input image; searching in the signature of the input image for at least one of the first identifiers; and determining that the input image may include the object when the signature of the input image may include at least one of the first identifiers.

The method may include generating location information indicative of a location of each region of interest within each image; wherein the generating movement information may be based on the location information.

There may be provided a non-transitory computer readable medium for movement based object detection, the non-transitory computer readable medium may include receiving or generating a video stream that may include a sequence of images; generating image signatures of the images; wherein each image may be associated with an image signature that may include identifiers; wherein each identifier identifiers a region of interest within the image; wherein different region of interests include different objects; generating movement information indicative of movements of the regions of interest within consecutive images of the sequence of images; searching, based on the movement information, for a first group of regions of interest that follow a first movement; and linking between first identifiers that identify the first group of regions of interest.

The linking may include linking between first image signatures that include the first linked identifiers.

The linking may include adding the first image signatures to a first concept structure, the first concept structure may be associated with the first image.

The non-transitory computer readable medium may store instructions for receiving or generating an input image; generating a signature of the input image; comparing the signature of the input image to signatures of the first concept structure; and determining that the input image may include a first object when at least one of the signatures of the first concept structure matches the signature of the input image.

The non-transitory computer readable medium may store instructions for receiving or generating an input image; generating a signature of the input image; searching in the signature of the input image for at least one of the first identifiers; and determining that the input image may include the object when the signature of the input image may include at least one of the first identifiers.

The non-transitory computer readable medium may store instructions for generating location information indicative of a location of each region of interest within each image; wherein the generating movement information may be based on the location information.

There may be provided an object detector that may include an input that may be configured to receive a video stream that may include a sequence of images; a signature generator that may be configured to generate image signatures of the images; wherein each image may be associated with an image signature that may include identifiers; wherein each identifier identifiers a region of interest within the image; a movement information unit that may be is configured to generate movement information indicative of movements of the regions of interest within consecutive images of the sequence of images; an object detection determination unit that may be configured to search, based on the movement information, for a first group of regions of interest that follow a first movement; wherein different first regions of interest may be associated with different parts of an object; and link between first identifiers that identify the first group of regions of interest.

The linking may include linking between first image signatures that include the first linked identifiers.

The linking may include adding the first image signatures to a first concept structure, the first concept structure may be associated with the first image.

The input may be configured to receive an input image; wherein the signature generator may be configured to generate a signature of the input image; and wherein the object detection determination unit may be configured to compare the signature of the input image to signatures of the first concept structure; and to determine that the input image may include a first object when at least one of the signatures of the first concept structure matches the signature of the input image.

The input may be configured to receive an input image; wherein the signature generator may be configured to generate a signature of the input image; and wherein the object detection determination unit may be configured to search in the signature of the input image for at least one of the first identifiers; and to determine that the input image may include the object when the signature of the input image may include at least one of the first identifiers.

The object detector that may be configured to generate location information indicative of a location of each region of interest within each image; wherein the generating of the movement information may be based on the location information.

While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention as claimed.

In the foregoing specification, the invention has been described with reference to specific examples of embodiments of the invention. It will, however, be evident that various modifications and changes may be made therein without departing from the broader spirit and scope of the invention as set forth in the appended claims.

Moreover, the terms “front,” “back,” “top,” “bottom,” “over,” “under” and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein.

Furthermore, the terms “assert” or “set” and “negate” (or “deassert” or “clear”) are used herein when referring to the rendering of a signal, status bit, or similar apparatus into its logically true or logically false state, respectively. If the logically true state is a logic level one, the logically false state is a logic level zero. And if the logically true state is a logic level zero, the logically false state is a logic level one.

Those skilled in the art will recognize that the boundaries between logic blocks are merely illustrative and that alternative embodiments may merge logic blocks or circuit elements or impose an alternate decomposition of functionality upon various logic blocks or circuit elements. Thus, it is to be understood that the architectures depicted herein are merely exemplary, and that in fact many other architectures may be implemented which achieve the same functionality.

Any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality may be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected,” or “operably coupled,” to each other to achieve the desired functionality.

Furthermore, those skilled in the art will recognize that boundaries between the above described operations merely illustrative. The multiple operations may be combined into a single operation, a single operation may be distributed in additional operations and operations may be executed at least partially overlapping in time. Moreover, alternative embodiments may include multiple instances of a particular operation, and the order of operations may be altered in various other embodiments.

Also for example, in one embodiment, the illustrated examples may be implemented as circuitry located on a single integrated circuit or within a same device. Alternatively, the examples may be implemented as any number of separate integrated circuits or separate devices interconnected with each other in a suitable manner.

However, other modifications, variations and alternatives are also possible. The specifications and drawings are, accordingly, to be regarded in an illustrative rather than in a restrictive sense.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word ‘comprising’ does not exclude the presence of other elements or steps then those listed in a claim. Furthermore, the terms “a” or “an,” as used herein, are defined as one or more than one. Also, the use of introductory phrases such as “at least one” and “one or more” in the claims should not be construed to imply that the introduction of another claim element by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim element to inventions containing only one such element, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an.” The same holds true for the use of definite articles. Unless stated otherwise, terms such as “first” and “second” are used to arbitrarily distinguish between the elements such terms describe. Thus, these terms are not necessarily intended to indicate temporal or other prioritization of such elements. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to advantage.

While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

It is appreciated that various features of the embodiments of the disclosure which are, for clarity, described in the contexts of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features of the embodiments of the disclosure which are, for brevity, described in the context of a single embodiment may also be provided separately or in any suitable sub-combination.

It will be appreciated by persons skilled in the art that the embodiments of the disclosure are not limited by what has been particularly shown and described hereinabove. Rather the scope of the embodiments of the disclosure is defined by the appended claims and equivalents thereof 

We claim:
 1. A method for scale invariant object detection, the method comprises: receiving or generating a first image in which an object appears in a first scale and a second image in which the object appears in a second scale that differs from the first scale; generating a first image signature and a second image signature; wherein the first image signature comprises a first group of at least one certain first image identifier that identifies at least a part of the object; wherein the second image signature comprises a second group of certain second image identifiers that identify different parts of the object; wherein each one of the at least one certain first image identifier differs from each one of the certain second image identifiers and wherein the second group is larger than it first group; linking between the at least one certain first image identifier and the certain second image identifiers; receiving or generating an input image; providing an amended image by changing a scale of the input image from the second scale to the first scale; generating a signature of the amended input image; and verifying that the input image comprises the object when the signature of the amended input image comprises the at least one certain first image identifier.
 2. The method according to claim 1 comprising linking between the first image signature, the second image signature and the object.
 3. The method according to claim 1 wherein the linking comprises adding the first signature and the second signature to a certain concept structure that is associated with the object.
 4. The method according to claim 3 comprising: receiving or generating an input image; generating a signature of the input image; comparing the signature of the input image to signatures of the certain concept structure; and determining that the input image comprises the object when at least one of the signatures of the certain concept structure matches the signature of the input image.
 5. The method according to claim 1 comprising: generating a signature of the input image, the signature of the input image comprises only some of the certain second image identifiers; wherein the input image is of the second scale.
 6. The method according to claim 1 comprising: receiving or generating an input image; generating a signature of the input image; searching in the signature of the input image for at least one of (a) the at least one certain first image identifier, and (b) the certain second image identifiers; and determining that the input image comprises the object when the signature of the input image comprises the at least one of (a) the at least one certain first image identifier, and (b) the certain second image identifiers.
 7. The method according to claim 1 comprising: receiving or generating an input image; generating a signature of the input image; searching in the signature of the input image for at least one of (a) one or more certain first image identifier of the at least one certain first image identifier, and (b) at least one certain second image identifier of the certain second image identifiers; and determining that the input image includes the object when the signature of the input image comprises the at least one of (a) one or more certain first image identifier of the at least one certain first image identifier, and (b) the at least one certain second image identifier.
 8. A non-transitory computer readable medium for scale invariant object detection, the non-transitory computer readable medium stores instructions for: receiving or generating a first image in which an object appears in a first scale and a second image in which the object appears in a second scale that differs from the first scale; generating a first image signature and a second image signature; wherein the first image signature comprises a first group of at least one certain first image identifier that identifies at least a part of the object; wherein the second image signature comprises a second group of certain second image identifiers that identify different parts of the object; wherein each one of the at least one certain first image identifier differs from each one of the certain second image identifiers and wherein the second group is larger than the first group; linking between the at least one certain first image identifier and the certain second image identifiers; receiving or generating an input image; providing an amended image by changing a scale of the input image from the second scale to the first scale; generating a signature of the amended input image; and verifying that the input image comprises the object when the signature of the amended input image comprises the at least one certain first image identifier.
 9. The non-transitory computer readable medium according to claim 8 that stores instructions for linking between the first image signature, the second image signature and the object.
 10. The non-transitory computer readable medium according to claim 8 wherein the linking comprises adding the first signature and the second signature to a certain concept structure that is associated with the object.
 11. The non-transitory computer readable medium according to claim 10 that stores instructions for: receiving or generating an input image; generating a signature of the input image; comparing the signature of the input image to signatures of the certain concept structure; and determining that the input image comprises the object when at least one of the signatures of the certain concept structure matches the signature of the input image.
 12. The non-transitory computer readable medium according to claim 8 that stores instructions for: generating a signature of the input image, the signature of the input image comprises only some of the certain second image identifiers; wherein the input image is of the second scale.
 13. The non-transitory computer readable medium according to claim 8 that stores instructions for: receiving or generating an input image; generating a signature of the input image; searching in the signature of the input image for at least one of (a) the at least one certain first image identifier, and (b) the certain second image identifiers; and determining that the input image includes the object when the signature of the input image comprises the at least one of (a) the at least one certain first image identifier, and (b) the certain second image identifiers.
 14. The non-transitory computer readable medium according to claim 8 that stores instructions for: receiving or generating an input image; generating a signature of the input image; searching in the signature of the input image for at least one of (a) one or more certain first image identifier of the at least one certain first image identifier, and (b) at least one certain second image identifier of the certain second image identifiers; and determining that the input image includes the object when the signature of the input image comprises the at least one of (a) one or more certain first image identifier of the at least one certain first image identifier, and (b) the at least one certain second image identifier.
 15. An object detector for scale invariant object detection, that comprises: an input that is configured to receive a first image in which an object appears in a first scale and a second image in which the object appears in a second scale that differs from the first scale; a signature generator that is configured to generate a first image signature and a second image signature; wherein the first image signature comprises a first group of at least one certain first image identifier that identifies at least a part of the object; wherein the second image signature comprises a second group of certain second image identifiers that identify different parts of the object; wherein each one of the at least one certain first image identifier differs from each one of the certain second image identifiers and wherein the second group is larger than & first group; an object detection determination unit that is configured to link between the at least one certain first image identifier and the certain second image identifiers; receiving or generating an input image; wherein the input is configured to receive an amended input image that was generated by changing a scale of the input image from the second scale to the first scale; wherein the signature generator is configured to generate a signature of the amended input image; and wherein the object detection determination unit is configured to verify that the input image comprises the object when the signature of the amended input image comprises the at least one certain first image identifier.
 16. The object detector according to claim 15 wherein the object detection determination unit is configured to link between the first image signature, the second image signature and the object.
 17. The object detector according to claim 15 wherein the object detection determination unit is configured to add the first signature and the second signature to a certain concept structure that is associated with the object.
 18. The object detector according to claim 17 wherein the input is configured to receive an input image; wherein the signal generator is configured to generate a signature of the input image; wherein the object detection determination unit is configured to compare the signature of the input image to signatures of the certain concept structure, and to determine that the input image comprises the object when at least one of the signatures of the certain concept structure matches the signature of the input image.
 19. The object detector according to claim 15, wherein the signature generator is configured to generate a signature of the input image, the signature of the input image comprises only some of the certain second image identifiers; wherein the input image is of the second scale.
 20. The object detector according to claim 15, wherein the input is configured to receive an input image; wherein the signature generator is configured to generate a signature of the input image; wherein the object detection determination unit is configured to search in the signature of the input image for at least one of (a) the at least one certain first image identifier, and (b) the certain second image identifiers; and determine that the input image includes the object when the signature of the input image comprises the at least one of (a) the at least one certain first image identifier, and (b) the certain second image identifiers.
 21. The object detector according to claim 15 wherein the input is configured to receive an input image; wherein the signature generator is configured to generate a signature of the input image; wherein the object detection determination unit is configured to search in the signature of the input image for at least one of (a) one or more certain first image identifier of the at least one certain first image identifier, and (b) at least one certain second image identifier of the certain second image identifiers; and determine that the input image includes the object when the signature of the input image comprises the at least one of (a) one or more certain first image identifier of the at least one certain first image identifier, and (b) the at least one certain second image identifier. 